Do you mean he "Flex Seal" we see with the guy sealing leaky boats, leaky basement windows, etc., etc.
If so, then it is a liquid rubber, and I have no doubt the clear will work for YOUR application. It will not bring out the "pop" or ultra clear and depth that many of our preferred coatings do, but, and I want to emphasize this, there is not ONE clear coat for every application.
No doubt it will not hold up well to pike or Muskie teeth, but I bet it will hold up to crappie and trout and similar small tooth critters very well.